DE934583C - Process and device for the regeneration of finely divided, non-combustible solid substances, in which first the more easily removable carbonaceous deposits are removed with a stripping gas and then the remaining carbonaceous deposits are removed by burning them out in a gas that supports the combustion, swirling layer - Google Patents

Description

ISSUED OCTOBER 27, 1955

N 6o66IVb / i2g

In many processes in which powdery, non-flammable solid impacts, such as discoloration Filter aids and catalysts, with an oil or other carbonaceous liquids or vapors come into contact, the solid body with carbonaceous material contaminates, which affects their effectiveness; So it is necessary to use the carbonaceous Contamination from time to time by a

removing regenerative treatment. The ge ίο Regenerative treatment used habitually is that the greater part of the easier to removing impurities is removed by a stripping treatment, followed by the remaining Impurities are burned out.

The fluidized bed process is advantageous for the regeneration of such contaminated solids applied. In this way of working

if the solid is in powder form (i.e. in the form of particles about a diameter of approx. ι mm or below) by venting with a gas or steam during the treatment in kept in a liquid-like state. This way of working, which is used when regenerating such solid Substances used on a large scale allows better temperature control and has also the advantage that it can be carried out simply in terms of apparatus.

The equipment used here is of two different types. With the boilers the upper trigger is the powdery one. Solid on top as a dilute suspension with the aeration gas deducted. In the case of the kettles with a bottom vent, the powdery solid becomes some Subtracted point in the fluidized bed downwards as a pseudo-liquid.

According to the invention, .20 of the finely divided, non-combustible solids are initially used for regeneration the more easily removable carbonaceous precipitates with a stripping gas and on it the remaining carbonaceous precipitates by burning out with an incineration supporting gas removed. Both treatments take place next to each other in the fluidized bed Zones which are in indirect heat exchange with one another, with a continuous Recirculation of part of the solid swirling up and down vigorously from the combustion zone into the Stripping zone takes place. The proportion of the fluidized solid that flows from the combustion zone into the stripping zone is returned, is above the stripping zone in a fluidized bed of the finely divided Solids passed, with this bed a seal between 'the stripping zone and the burnout zone forms, whereupon the powder is fed from said bed into the stripping zone.

There. the bed of fluidized solids acting as a seal prevents the The process enables material flowing out of the stripping zone to be mixed with the heating gases according to the present invention that the valuable stripped products contained in this outflowing electricity are included, can easily be obtained.

An apparatus for carrying out the method according to the invention is shown below Hand of the drawings explained.

Figure I is a vertical section through the regenerator ;

Fig. II is a view (partially in section) of the same device, this is compared with the position in Figure 1 rotated 90 ^0th; FIGS. IHj IV and V are cross-sections in the planes IH-III, IV-IV and VV according to FIG. 1.

As can be seen from the figures, the Device consisting of a cylindrical boiler with an outer jacket 1. The bottom closure can, be elliptical as shown. The upper part is expanded to a larger cross-section. The cauldron is divided into two sections called the stripping zone and the burn zone. For this serves a vertical partition 2, which extends to a point just above the ground. The stripping zone, which is located to the left of the partition wall according to FIG. 1, is at the upper end Completed against the combustion zone by a trough 3. At least one open pipe 4 extends from the bottom of the trough down into the stripping zone to a point below normal Surface of the fluidized bed. The lead-in line 5 for the solid to be treated Material flows into the stripping zone below the trough. Abfü'hrungslinien 6 for stripped Products extend from the top of the stripping zone through the trough and end outside the upper end of the boiler. These discharge lines are preferably equipped with cyclone separators 7 provided, which carry down extensions 8, which are in the fluidized bed extend into it. The stripping zone is divided into cells by partition walls 9. The partitions 9 extend upward only so far that they are below the normal surface of the fluidized bed lie. To the right of the partition 2, i. H. lines 10 extend in the combustion zone from a point below the normal surface of the fluidized bed up to a point above the partition wall 2. These lines open into the trough. Lines 11 running through Passed through the floor are arranged to allow gas into the lower ends of the conduits 10 submit. The device is equipped with the usual cyclone separators 12 and discharge lines 13 for the heating gas, an outlet 14 for the regenerated solid matter, an introduction opening ^ for regeneration gas 15, a gas distribution grate 16 and a branched supply pipe 17 for stripping gas.

The device works as follows: The contaminated solid is through line 5 in the stripping zone introduced. The powdery solid matter is in the form of a fluidized bed held, which has about the drawn upper boundary surface. The whirled up Solid flows in the stripping zone in countercurrent to that through the branched distribution pipe 17 introduced stripping steam downwards. The powder that has been stripped off then flows under the partition 2 into the burnout zone. After burning out the remaining carbonaceous impurities the regenerated solid is drawn in with air introduced through line 15 through line 14. A quantity of air or other gas is introduced through the line 11. This gas picks up suspended solid particles and transports them with the Gas flow through line 10 into trough 3. The gas used to transport and the heating gas flow out of the boiler through the cyclone separator 12 and the line 13. The stripping steam and the stripped material pass from the stripping zone via the cyclone separators 7 and the lines 6 to the outside. The stripped product: can then be won for itself, The

swirled solid, which has been deposited in the trough 3, passes through the lines 4 in the stripping zone. As a result of the heat exchange between the stripping zone and the burning zone and by mixing the hotter particles which are introduced via trough 3 and line 4, the temperature in the stripping zone is increased. At the same time, the whirled up powder seals in removes the stripping zone from the trough and enables the stripped products to be recovered separately. According to the present invention, the stripping is carried out under positive pressure. This requires a special arrangement of the various boilers, pipes, etc., when looking at the device as part of a fluidized catalyst system, e.g. B. a catalytic Splitting line, used. Some of the most important features of the system so formed are the following:

No risers are required. Risers are not only expensive to install and in entertainment in view of the serious erosion damage to which they have been subjected are, but their application also requires a large amount of energy. If you have the system When used in the present invention, the reaction vessel and regenerator can essentially be arranged at the same height. This altitude corresponds essentially to that of the soil. In this way, low overall heights can be achieved. This is not only beneficial with a view to avoiding excessively long pipes, large heat losses, etc., but also leads to a system which can be created with significantly lower costs, since only low costs Expenses for steel shoring are required. To get the static pressures, which are necessary for working with the apparatus is the use of a long, narrow reaction vessel required, in which the speeds are higher than before than considered normal. A great length to diameter ratio and the high speed both increase the efficiency of the reaction vessel considerably. The used powder can also be stored in a small primary zone, which immediately adjoins the reaction vessel, be stripped prior to the main stripping treatment. This treatment can be in that small exhaust duct inside the reaction vessel at the top of the flue pipe is arranged. This makes this possible when used in a catalytic cracking plant the achievement of considerable yields of highly concentrated polynuclear aromatics from the Main stripping zone. Inert combustion gases can be released from the hot regenerated powder rapidly and can be blown off in a very simple way by putting at the bottom of the designated stripping zone Spraying steam. By removing these inert gases, the burden of the recovery becomes of the part of the system serving hydrocarbon gas is significantly reduced.

In the drawings, Fig. VI is a view (partially in section) of the main part of a catalytic one Splitting line.

VII and VIII are cross-sections through the two larger boilers in levels II-II and III-III according to FIG. VI.

According to Fig. VI, the device contains a reaction vessel 25. The bottom of this kettle is approximately at the level of the bottom end. The cauldron itself is long and narrow and must create a fluidized bed which has a minimum ratio of Height to diameter of at least 6, in particular between 7 and 13. According to a preferred Embodiment, this kettle has a diameter of 230 cm in the lower part and a length up to the height at which it expands of 1830 cm. It is also important that the kettle has at least one Height of 460 cm is extended. For example, the upper expanded portion has a diameter of 460 cm and a height of 460 cm as well. This is used to generate the high flow velocity, which is necessary for the operation of the apparatus. The purpose of the extension is to accommodate the lower To bring about speed, which is necessary for the regulation and a withdrawal of the suspended catalyst allows. A minimum length of the extended section of 460 cm is the lowest limit, which is the case with the usual fission catalysts and a superficial gas velocity 33 cm per second enables a separation.

The oil to be converted is fed into the catalyst bed directly at the bottom with the aid of the distributor 26 introduced. After flowing through a conventional cyclone separator, the vapors of the withdrawn converted oil at the upper end through the outlet opening 27.

In the plane in which the expansion begins, a short partition 28 is arranged, which forms a discharge duct 29 in the conical part.

Hot regenerated catalyst is through the standpipe 30, which is provided with control valve 31, fed directly to the bottom of the reaction vessel under the action of gravity. Consumed Catalyst is from the exhaust duct 29 under the action of gravity by the Standpipe 32 provided with valve 33 is withdrawn.

The regenerator 34 is arranged next to the reaction vessel; its bottom is also about at the height of the floor finish. This is necessary to create the static pressures which are required for the desired flow of powder. The regeneration boiler 34 is just like the reaction vessel 25 at the upper end over a length of at least 460 cm to an iao enlarged diameter in order to reduce the speed and a separation space to accomplish.

The regenerator 34 is provided with a vertical partition wall 35, which is like a The tendon extends from wall to wall and

In the horizontal section, the boiler is divided into a smaller stripping zone on the left and a larger one Dividing burnout zone on the right. The burnout zone of the regeneration boiler should, like that Reaction vessel; have a high ratio between height and effective diameter. So is in the case shown in the drawing, the cross-sectional area of the burnout zone below of the conical part 16.75 square meters, and the height is 1680 cm. The wall 35 extends from a point near the plane in which the expansion begins to a point in the Near the bottom of the boiler, which is so far away from it that there is a passage opening for the fluidized powder to flow through from the stripping zone below the partition remains in the burnout zone.

A partition 36 is provided in the upper part of the token zone .below the extension and so on arranged that this zone in an upper stripping zone and disassembling a separate lower stripping zone. The upper zone is preferably vertical Guide plates 37 are provided which divide the zone into a series of long, narrow, open ended channels disassemble. The stripping gas is introduced into the upper zone through manifold 38. The above mentioned line 30 is in communication with the lower part of this upper stripping zone.

The lower stripping zone is similarly expedient with guide plates 39, similar to the plates 37, and also equipped with supply pipes 40 to a gaseous stripping medium to introduce. The line 32 runs through the wall of the boiler and is arranged so that it is in the central portion of the lower stripping zone above the vertical guide plates 39 and below the Partition 36 opens. A mixing or distribution plate 18 is just below the end of the Line 32 is provided. Another line 19 with control valve 20 connects the upper and lower Stripping zone. This line, which passes through the tight partition wall 36, thus enables the regulated flow of the fluidized powder from the lower end of the upper zone to the mixing pan 18th

The regeneration boiler is also provided with a discharge line 21 which has a check valve 22 contains. This line is as high as possible in the lower stripping zone just below the

5.0 Partition 36 is connected to this zone and can be connected to the separation zone in the reaction vessel are, the cyclones in the reaction vessel are used to remove any suspended catalyst from the To win stripping gas. The boiler is at the top also with a discharge line 23 and also with a suitable manifold 24 for introducing air at the bottom on the right side of the partition 35 provided.

At the high speeds ensured by the narrow reaction zone and the burning zone a low density of fluidized powder is maintained in the zones. This low density combined with the considerable height creates a sufficient difference between the static pressure of these beds and that of the denser powder in the connecting lines 30, 32 and 19, so that the desired River is brought about. For example, the effective pressure in the reaction vessel is between 1.61 atmospheres at the lower end and 0.91 atmospheres in the separation zone. The effective pressure in the regeneration boiler is between 1.61 atmospheres at the bottom and 0.98 atmospheres in the separation zone. In these circumstances, a Pressure drop across valves 31, 33 and 20 of 0.14 atmospheres, and valve 22 is adjusted so that it can withstand a back pressure of 1.26 atmospheres.

The stripping of the spent catalyst, which is discharged from the reaction vessel through line 32, is carried out under a controlled back pressure. This counter pressure is regulated in order to keep the surface of the fluidized powder in the lower stripping zone at a level above the plates 39 and below the mixing plate 18, as indicated for example by the letter A in the drawing. Hot regenerated catalyst flows over the top of wall 35 into the upper stripping zone. A portion of the catalyst is withdrawn through line 30 and fed to the reaction vessel. A second part controlled by the valve 20 flows under the action of gravity against the counter pressure into the lower stripping zone, where it is mixed with the used catalyst on the mixing plate 18. The hot mixture then falls freely over a short distance in countercurrent to the rising wipers and is finally wiped off in a fluidized bed in the lower part of the lower wiping zone. The stripping gas with the stripped products is discharged from the device through line 21 and valve 22.

The valve 20 is an automatically regulated slide. In the one shown in the drawings In the system, this valve is located within the lower stripping zone. If desired, can the line 19 can be arranged so that the valve is arranged more easily accessible outside.

Claims (6)

110 PATENT CLAIMS: I, a process for the regeneration of finely divided, non-combustible solid substances, in which first the more easily removable carbonaceous precipitates _{are removed with a stripping gas n 5} and then the remaining carbonaceous precipitates are removed by burning out in a gas that supports the combustion, in a swirling layer and in separate layers neighboring ones in indirect heat exchange! Zones, being part of the lively on and continuously. from whirling solid is returned from the burnout zone to the stripping zone, characterized in that the solid returned from the burnout zone into the stripping zone is converted into a above the bed forming a seal between the stripping zone and the burning zone Stripping zone is lifted and then guided into the stripping zone. 2. Process for regenerating finely divided solid substances according to claim i, characterized in that that the part of the fluidized solid material returned from the combustion zone is at a level above the normal surface level ίο the fluidized bed is promoted in the combustion zone. 3. The method according to claim 1 or 2, characterized in that the stripping zone and the burning zone are at about the same height, the stripped solid continuously from Bottom of the stripping zone led to the bottom of the burning zone and part of the whirled up Solid continuously passed up from the burn zone to a bed above the stripping zone is and flows from there into the stripping zone, the stripping gas and the fuel gas from the The stripping zone and the burning zone are removed separately. 4. Apparatus for performing the method according to claim 1 to 3, consisting of a vertically arranged, closed at the top and bottom, with a supply line for the regeneration gas on the ground, an outlet opening for the used regeneration gas at the top and an outlet opening for regenerated fluidized solids between the two openings provided boiler, which has the following features, a) a trough arranged in the upper part with at least one from the bottom of the same after standpipe that extends at the bottom and is open at the ends, b) a partition which extends from the side of the trough to a point just above the Boiler bottom and divides the boiler into a stripping zone and a burning zone, c) a supply line for the fluidized solids to be regenerated on upper end of the stripping zone, but below the trough, d) a line with open ends extending from the separation zone to a point above of the trough and supply lines for gas at the lower end of this line, e) a supply line for stripping gas to Stripping zone at the lower end of the partition and a drain pipe for the stripping gas on upper end of the stripping zone. 5. Apparatus according to claim 4, characterized in that the boiler a) has a larger cross-section near the upper end, b) through a partition wall extending perpendicularly from wall to wall into a smaller stripping and a larger burn-out zone is divided, the stripping zone through a second horizontal partition is divided into an upper and a lower zone, c) a mixing plate in the boiler central 'in the lower stripping zone is arranged with a feed line for the contaminated to be treated Contact ground, d) a standpipe provided with a valve to regulate the flow rate therein it is provided that through the horizontal partition a connection of the upper stripping zone to the mixing plate in the lower stripping zone, e) a discharge line for withdrawing the treated contact mass from the upper one Stripping zone and a discharge line with a non-return valve to discharge the treatment gases are provided from the lower stripping zone below the horizontal partition. 6. Apparatus according to claim 5, characterized in that a) in the lower part of the upper and lower stripping zone vertical guide plates, the zones in split long, narrow channels, b) the mixing plate is arranged in the lower stripping zone above the guide plates, c) the supply lines for the stripping gas in the lower and the upper stripping zone open at about the level of the lower edges of the guide plates, d) Supply lines for air at various points near the bottom of the Burnout zone are provided. Cited references: U.S. Patents Nos. 2,401,739, 2,617,708. 1 sheet of drawings © 509561 10.5S